CN111602460A

CN111602460A - User device and preamble transmission method

Info

Publication number: CN111602460A
Application number: CN201980006941.7A
Authority: CN
Inventors: 小原知也
Original assignee: NTT Korea Co Ltd
Current assignee: NTT Korea Co Ltd
Priority date: 2018-01-25
Filing date: 2019-01-22
Publication date: 2020-08-28
Anticipated expiration: 2039-01-22
Also published as: JP7084947B2; US11277870B2; WO2019146574A1; EP3745804A1; RU2754024C1; CN111602460B; EP3745804A4; JPWO2019146574A1; BR112020014532A2; CO2020010264A2; KR20200110742A; US20210378016A1; KR102388787B1

Abstract

A user device is provided with: a reception unit that detects a synchronization signal or a physical broadcast channel from a base station; a control unit that selects a resource for transmitting a preamble from the detected synchronization signal or physical broadcast channel, based on a mapping rule, from among resources determined based on setting information for preamble transmission, according to a cycle determined based on a synchronization signal burst set cycle, which is a period during which the synchronization signal or physical broadcast channel can be transmitted, a resource cycle that can be used for preamble transmission, and a time during which mapping of the synchronization signal or broadcast channel in the synchronization signal burst set can be completed; and a transmission unit configured to transmit a preamble to the base station in the selected resource.

Description

User device and preamble transmission method

Technical Field

The present invention relates to a user equipment and a preamble transmission method.

Background

In 3GPP (Third Generation Partnership Project), the next Generation communication standards (5G or NR) of LTE (Long Term Evolution) and LTE-Advanced are being discussed. In the NR system, it is also assumed that random access is performed when a User Equipment (UE) establishes a connection with a base station (eNB or eNodeB) or when the User Equipment is reconnected, as in the case of LTE or the like.

In the Random Access of LTE, a Channel for initially transmitting a preamble is called a Physical Random Access Channel (PRACH), and setting information (RACHConfiguration) related to the PRACH is reported from a base station to a user equipment by an index. That is, the user equipment selects a resource of a PRACH (hereinafter, referred to as an RACH resource) based on RACH configuration (RACHConfiguration) notified from the base station (see non-patent document 1).

Documents of the prior art

Non-patent document

Non-patent document 1: 3GPP TS36.211 V14.2.0(2017-03)

Disclosure of Invention

Problems to be solved by the invention

In NR, it is also assumed that the user equipment selects a RACH resource based on RACH configuration (RACHConfiguration) reported from the base station, as in LTE. In NR, a mechanism capable of repeatedly transmitting a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH) in the time direction is studied. Resources configured with PSS, SSS, or PBCH are referred to as SS blocks (SS blocks), and repetitions of SS blocks are referred to as SS burst sets (SSburst sets). It is assumed that, when an SS block is detected, the user equipment selects an RACH resource from a plurality of resources specified by RACH configuration (RACHConfiguration).

However, the number of RACH resources required to transmit a preamble from an SS block in an SS burst set depends on the number of SS blocks in the SS burst set, and the like, and there is no match with the number of RACH resources determined from RACH Configuration (RACH Configuration).

The purpose of the present invention is to provide a mechanism for appropriately deciding the period for selecting a RACH resource from SS blocks in an SS burst set.

Means for solving the problems

A user device according to an embodiment of the present invention includes:

a reception unit that detects a synchronization signal or a physical broadcast channel from a base station;

a control unit that selects a resource for transmitting a preamble from the detected synchronization signal or physical broadcast channel, based on a mapping rule, from among resources determined from setting information for preamble transmission, according to a cycle determined based on a synchronization signal burst set cycle, which is a period during which the synchronization signal or physical broadcast channel can be transmitted, a resource cycle available for preamble transmission, and a time during which mapping of the synchronization signal or broadcast channel in the synchronization signal burst set can be completed; and

a transmission unit configured to transmit a preamble to the base station in the selected resource.

Effects of the invention

According to the present invention, the period for selecting RACH resources from SS blocks in an SS burst set can be appropriately determined.

Drawings

Fig. 1 is a schematic diagram of a wireless communication system in an embodiment of the present invention.

Fig. 2 is a diagram showing a correspondence relationship between SS blocks and RACH resources.

Fig. 3 is a diagram illustrating an example of determining a mapping period.

Fig. 4 is a timing diagram showing a preamble transmission procedure in the wireless communication system according to the embodiment of the present invention.

Fig. 5 is a diagram of specific example 1 of selecting RACH resources for transmitting preambles.

Fig. 6 is a diagram of specific example 2 of selecting RACH resources for transmitting a preamble.

Fig. 7 is a diagram of specific example 3 of selecting RACH resources for transmitting preambles.

Fig. 8 is a block diagram showing an example of a functional configuration of a base station.

Fig. 9 is a block diagram showing an example of the functional configuration of the user apparatus.

Fig. 10 is a diagram showing an example of a hardware configuration of a wireless communication apparatus according to an embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. The embodiments described below are merely examples, and embodiments to which the present invention is applied are not limited to the embodiments described below.

In the present embodiment, terms defined by LTE are used as appropriate for the description. Further, when the wireless communication system operates, the existing technology specified by LTE can be appropriately used. However, the related art is not limited to LTE. In addition, "LTE" as used in this specification is used in a broad sense including LTE-Advanced and the way after LTE-Advanced, unless otherwise specified. In the present embodiment, the preamble transmission at the time of random access is described, but the present invention can also be applied to the preamble transmission at any timing after synchronization with the base station.

Note that, in the present embodiment, terms such as PSS, SSS, PBCH, RACH, preamble, and the like used in the conventional LTE are used, but this is for convenience of description, and signals and the like similar to these may be referred to by other names.

< overview of Wireless communication System >

Fig. 1 is a configuration diagram of a wireless communication system 10 according to the present embodiment. As shown in fig. 1, a radio communication system 10 according to the present embodiment includes a base station 100 and a user equipment 200. In the example of fig. 1, one base station 100 and one user apparatus 200 are shown, but a plurality of base stations 100 and a plurality of user apparatuses 200 may be provided. Base station 100 may be referred to as a BS and user equipment 200 may be referred to as a UE.

The base station 100 can accommodate 1 or more (e.g., 3) cells (also referred to as sectors). When the base station 100 accommodates a plurality of cells, the entire coverage area of the base station 100 can be divided into a plurality of smaller areas, and each of the smaller areas can also provide a communication service through a base station subsystem (e.g., a small indoor base station RRH: Remote radio head). The term "cell" or "sector" refers to a portion or the entirety of the coverage area of a base station and/or base station subsystem that is in communication service within the coverage area. The terms "base station", "eNB", "cell", and "sector" are used interchangeably in this specification. The base station 100 may be referred to by terms such as a fixed station (fixed station), NodeB, eNodeB (eNB), access point (access point), femto cell, and small cell.

With respect to user device 200, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent (usergent), a mobile client, a client, or some other suitable terminology will sometimes be referred to, depending on the skilled artisan.

In order to compensate for propagation loss in high frequencies, the base station 100 or the user equipment 200 can apply beamforming with a narrow beam width. When a beamforming transmission signal is applied, the base station 100 or the user apparatus 200 performs beam scanning (beam sweeping) or the like to determine the direction of a transmission beam (Tx-beam) so that the reception quality on the communication partner side becomes better. Similarly, when the beamforming reception signal is applied, the base station 100 or the user apparatus 200 determines the direction of the reception beam (Rx-beam) so that the reception quality from the communication partner side becomes good.

The random access is performed when the user equipment 200 establishes a connection with the base station 100, or when resynchronization is performed, for example, at the time of call origination or handover. In the random access, the user equipment 200 transmits a preamble (PRACH preamble) selected from a plurality of preambles prepared in a cell. When detecting a preamble, the base station transmits RAR (RACH response: RA response) as response information of the preamble. The user equipment having received the RAR transmits an RRC connection request (RRC connection request) as a message 3(message 3). After receiving the message 3(message3), the base station transmits an RRC connection setup (RRC ConnectionSetup) including cell setting information and the like for connection setup as a message 4(message 4). The user equipment whose own UE ID is included in the message 4(message4) completes the random access process and establishes a connection.

A Channel used for initially transmitting the preamble in the Random Access is called a Physical Random Access Channel (PRACH). The candidate set of the setup information (RACH Configuration) related to the PRACH is defined in advance in a Table called, for example, a RACH Configuration Table (RACH Configuration Table), and an index is assigned to each RACH setup (RACH Configuration). The base station 100 notifies the user equipment 200 of an index of the RACH Configuration Table (RACH Configuration Table) by using broadcast information or the like, and specifies the location, number, density, and the like of resources that can be used for transmission of the preamble. The user equipment 200 can determine a resource (i.e., RACH resource) that can be used for transmission of the preamble, based on the notified index (i.e., based on RACH Configuration corresponding to the notified index). The RACH resource is, for example, periodically configured in a predetermined portion of a resource composed of a time domain and a frequency domain. Further, RACH Configuration (RACH Configuration) may be replaced with Configuration information for preamble transmission.

The base station 100 can change the direction of a transmission beam, for example, and transmit PSS, SSs, or PBCH using a plurality of SS blocks within an SS burst set. The set of SS bursts repeats with a period of, for example, 20ms or the like. The maximum number L of SS blocks in an SS burst set varies depending on the frequency band, and is defined as L4 at 3GHz or less, L8 at 3 to 6GHz, and L64 at 6 to 52.6GHz, for example. Further, the base station is not necessarily limited to use of all L SS blocks, and the base station can use any number of SS blocks, which are actually transmitted from the base station, within L or less.

When detecting the PSS, SSS, or PBCH, the user equipment 200 selects RACH resources associated with an SS block in which the detected PSS, SSS, or PBCH is arranged, from among resources that can be used for transmission of a preamble. The user equipment 200 transmits a preamble in the selected RACH resource. By using the correspondence between the SS blocks and the RACH resources, the base station 100 can recognize which SS block in the SS burst set the user equipment 200 can detect. The correspondence between the SS blocks and the RACH resources is explained with reference to fig. 2.

Fig. 2 is a diagram showing a correspondence relationship between SS blocks and RACH resources. The user equipment 200 can determine resources (RACH resource 1, RACH resource 2, and RACH resource 3 … …) that can be used for preamble transmission by RACH Configuration (RACH Configuration). The mapping rule (mapping rule) defining the correspondence relationship between the SS blocks in the SS burst set and the RACH resources may be notified from the base station 100 to the user equipment 200 by broadcast information or the like, or may be defined in advance by a specification. The mapping rule can be arbitrarily defined, and for example, as shown in fig. 2, the mapping rule may be defined such that a preamble for SS block #1 is transmitted in RACH resource 1, and a preamble for SS block #6 is transmitted in RACH resource 2.

The user equipment 200 selects RACH resources associated with SS blocks configured with PSS, SSS, or PBCH, and transmits a preamble to the base station 100. For example, in the case where PSS, SSs, or PBCH is detected in SS block #6, the user equipment 200 selects RACH resource 2 associated with SS block # 6. Then, the user equipment 200 selects a preamble from the plurality of preambles available in the selected RACH resource 2, and transmits the preamble to the base station 100.

In addition, a plurality of RACH resources (a plurality of time resources or a plurality of frequency resources) may be selected for one SS block, or one RACH resource may be associated with a plurality of SS blocks. For example, RACH resources of 7, 6, 3, 2, 1, etc. in 1 slot may be selected for one SS block. The user equipment may also select 1 or more RACH resources randomly, for example, from among the selectable RACH resources, and transmit a preamble.

The mapping rule may be mapping from only SS blocks actually transmitted by the base station in the SS burst set, or may be mapping from the maximum number L of SS blocks in the SS burst set. Hereinafter, in the case of mapping only from the actually transmitted SS blocks in the SS burst set as described in the "all SS blocks in the SS burst set" or the like, the "all actually transmitted SS blocks in the SS burst set" is indicated, and in the case of mapping from the maximum number L of SS blocks in the SS burst set, the "L all SS blocks in the SS burst set" is indicated.

< example of mapping period >

Next, an example of determining a period (hereinafter, referred to as a mapping period) for selecting RACH resources from SS blocks based on a mapping rule will be described with reference to fig. 3. Fig. 3 is a diagram showing an example of determining a mapping period.

As described above, the RACH resource Configuration is determined according to the RACH Configuration (RACH Configuration), and as a result, the cycle of the RACH resource Configuration is also determined according to the RACH Configuration (RACH Configuration) (for example, the cycle is specified by the RACH Configuration Table).

For example, the RACH resource determined by RACH Configuration (RACH Configuration) is described by taking the following case as an example: in 2.5ms, there are 1 time slot in the time slot containing the RACH resource, the number of RACH resources in 1 time slot is 7, and the cycle of RACH resource configuration is 10 ms. Furthermore, the following is also envisaged: values that can be assumed as the SS burst set period are {5ms, 10ms, 20ms, 40ms, 80ms, 160ms }, and 20ms of these assumed values is used. Also, the following is assumed: 64 SS blocks are sent within a set of SS bursts, one SS block being mapped to one RACH resource.

The mapping from SS blocks to RACH resources is determined according to the mapping rule, but in this example, the time in which the mapping from all SS blocks within the SS burst set to RACH resources can be completed is 10 slots to 25 ms. Further, by setting the mapping period to 40ms, for example, according to the period (20ms) of the SS burst set, the period (10ms) of the RACH resource allocation, or a multiple thereof, it is possible to always set the position of the RACH resource to the SS block #0 as the first RACH resource in the mapping period (40 ms). Therefore, the base station can easily recognize which SS block the user equipment 200 can detect from the RACH resource on which the preamble is received.

On the other hand, in the example of fig. 3, when the mapping period is 20ms, all SS blocks cannot be mapped to RACH resources within 20 ms. Therefore, the mapping period is preferably a value equal to or more than the time when the mapping of all SS blocks in the SS burst set can be completed.

As described above, in the present embodiment, the mapping period is determined in accordance with the period of the SS burst set or the period of the RACH resource allocation as described below.

(1) The minimum value among values that can be taken as the SS burst set period and that is larger than the time in which mapping of all SS blocks within the SS burst set can be completed is used as the mapping period. In the example described with reference to fig. 3, the values that can be assumed as the SS burst set period are {5ms, 10ms, 20ms, 40ms, 80ms, 160ms }, and the time during which the mapping of all SS blocks within the SS burst set can be completed is 25 ms. In this example, 40ms is used as the mapping period.

(2) The minimum value among values that are greater than the time in which mapping of all SS blocks in an SS burst set can be completed, among multiples of the SS burst set period notified from the base station to the user equipment, is used as the mapping period. In the example described with reference to fig. 3, the SS burst set period notified from the base station to the user equipment is 20ms, and the time during which mapping of all SS blocks in the SS burst set can be completed is 25 ms. In this example, 40ms is used as the mapping period.

(3) The SS burst set period notified from the base station to the user equipment is used as the mapping period. In the example described with reference to fig. 3, the SS burst set period notified from the base station to the user equipment is 20ms, but the SS burst set period may be changed from 20ms to 40ms and the SS burst set period of 40ms may be notified from the base station to the user equipment, taking into account the time when the mapping of all SS blocks in the SS burst set can be completed in the base station.

(4) The minimum value among values larger than the time in which mapping of all SS blocks within an SS burst set can be completed among the multiples of the period of the RACH resource configuration is used as the mapping period. In the example described with reference to fig. 3, the period of RACH resource configuration is 10ms, and the time period in which mapping of all SS blocks in an SS burst set can be completed is 25 ms. In this example, 30ms is used as the mapping period.

(5) The period of the RACH resource configuration is used as the mapping period. In the example described with reference to fig. 3, the period of RACH resource allocation is 10ms and the time during which mapping of all SS blocks in an SS burst set can be completed is 25ms, but in order to complete mapping of all SS blocks in an SS burst set in the mapping period, the base station may notify the user equipment of RACH Configuration (RACH Configuration) in which mapping of all SS blocks in an SS burst set can be completed in 10ms (period of RACH resource allocation).

(6) The minimum value, which is a common multiple of the period of the SS burst set notified from the base station to the user equipment and the period of the RACH resource configuration, is larger than the time in which mapping of all SS blocks in the SS burst set can be completed, and is used as the mapping period. In the example described with reference to fig. 3, the SS burst set period notified from the base station to the user equipment is 20ms, the RACH resource configuration period is 10ms, and the least common multiple thereof is 20 ms. Furthermore, the mapping of all SS blocks within a set of SS bursts can be completed in 25 ms. In this example, 40ms is used as the mapping period.

(7) The minimum value among values that can be taken as a multiple of the period of RACH resource allocation, which is equal to or greater than the minimum value that is greater than the time in which mapping of all SS blocks in an SS burst set can be completed, among values that can be taken as a multiple of the period of RACH resource allocation, is used as the mapping period. In the example illustrated with reference to fig. 3, the period of RACH resource configuration is 10ms, and the time in which mapping of all SS blocks in an SS burst set can be completed is 25 ms. The minimum value of values that can be taken as a multiple of the period of the RACH resource configuration, which is greater than the time in which mapping of all SS blocks within an SS burst set can be completed, is 30 ms. Further, the SS burst set period notified from the base station to the user apparatus is 20 ms. In this example, 40ms is used as the mapping period.

(8) The minimum value among values that can be assumed as the period of the RACH resource configuration is equal to or greater than (equal to or greater than) the minimum value that is larger than the time in which the mapping of all SS blocks in the SS burst set can be completed, among values that can be assumed as multiples of the period. In the example illustrated with reference to fig. 3, the period of RACH resource configuration is 10ms, and the time in which mapping of all SS blocks in an SS burst set can be completed is 25 ms. The minimum value of values that can be taken as a multiple of the period of the RACH resource configuration, which is greater than the time in which mapping of all SS blocks within an SS burst set can be completed, is 30 ms. Further, values of {5ms, 10ms, 20ms, 40ms, 80ms, 160ms } may be taken as the SS burst set period. In this example, 40ms is used as the mapping period. Although the values that can be taken as the SS burst set period are {5ms, 10ms, 20ms, 40ms, 80ms, 160ms }, 5ms of these values may or may not be included in the values that can be taken as the SS burst set period.

(9) The mapping period is set to be the minimum value of values that can be taken as a multiple of the period of the RACH resource configuration, which is longer than the time in which mapping of all SS blocks in an SS burst set can be completed, and the maximum value of two values of the SS burst set period notified from the base station to the user equipment. In the example illustrated with reference to fig. 3, the period of RACH resource configuration is 10ms, and the time in which mapping of all SS blocks in an SS burst set can be completed is 25 ms. The minimum value of values that can be taken as a multiple of the period of the RACH resource configuration, which is greater than the time in which mapping of all SS blocks within an SS burst set can be completed, is 30 ms. Further, the SS burst set period notified from the base station to the user apparatus is 20 ms. In this example, 30ms is used as the mapping period.

Any combination of the above mapping periods (1) to (9) may be used. When a combination of these periods is used, which of the periods (1) to (9) is used may be notified from the base station to the user equipment by broadcast Information, RRC (radio resource Control) signaling, DCI (Downlink Control Information), or the like, or may be determined in advance according to specifications. In the case of using these combinations, a larger value or a smaller value may be used. For example, when a combination of the mapping period of (2) and the mapping period of (4) is used, the larger value or the smaller value of the two values is determined as the mapping period.

Instead of the user equipment, the base station or the network node may determine the mapping period and notify the user equipment of the mapping period by broadcast information, RRC signaling, DCI, or the like. Further, the value that can be taken as the mapping period can also be determined according to specifications. For example, the mapping period may be determined for each index of a RACH Configuration Table (RACH Configuration Table).

< example 1>

Next, specific example 1 of the preamble transmission procedure in the wireless communication system according to the present embodiment will be described in detail with reference to fig. 4 and 5. Fig. 4 is a timing diagram showing a preamble transmission procedure in the wireless communication system according to the embodiment of the present invention. Fig. 5 is a schematic diagram of specific example 1 of selecting a resource for transmitting a preamble.

The base station 100 transmits a PSS used for time synchronization, frequency synchronization, detection of a part of a cell ID, and the like, and an SSS used for detection of a cell ID, and the like, and also transmits a PBCH including a part of system information necessary for initial access to the user equipment 200 (S101). The PSS, SSS, or PBCH is configured in resources within a set of SS bursts called SS blocks and transmitted to the user equipment 200. User device 200 attempts to detect PSS, SSs, and PBCH within the set of SS bursts. When the PSS, SSS, and PBCH are detected, the user equipment 200 can also receive other system information transmitted through the PDSCH (Physical Downlink shared channel), for example. Here, the system information transmitted by PBCH and the system information transmitted by another channel such as PDSCH are collectively referred to as broadcast information.

The broadcast information notified to the user equipment 200 may include RACH Configuration (e.g., an index of a RACH Configuration Table), a mapping rule defining a correspondence relationship between the SS blocks in the SS burst set and the RACH resource, and a mapping cycle. In the present embodiment, the above information is described on the assumption that it is included in the broadcast information, but any one of the above information may be notified to the user equipment 200 by control information (for example, RRC signaling, DCI, or the like) other than the broadcast information, or may be defined in advance by a specification.

The user equipment 200 determines resources that can be used for preamble transmission based on RACH Configuration (RACH Configuration) included in the broadcast information. For example, as shown in fig. 5, it is determined by RACH configuration (RACHConfiguration) that 6 resources can be used in the time direction in 1 cycle (cycle of RACH resource allocation) of a certain specified period. Here, regarding the period of the RACH resource configuration, the period may be determined in consideration of the number of SS blocks within the SS burst set. For example, in a case where 8 SS blocks exist within an SS burst set and RACH resources in one time direction are used for one SS block, the period of RACH resource configuration is determined so that at least resources in 8 time directions can be utilized.

The mapping period from the SS block to the RACH resource may be determined according to the period of the SS burst set, the period of the RACH resource configuration, or the like, as described above.

The user equipment 200 selects a RACH resource associated with an SS block in which the detected PSS, SSs, or PBCH is arranged, from among resources that can be used for transmission of the preamble, using a mapping rule that specifies the correspondence relationship between the SS blocks in the SS burst set and the RACH resource. For example, as shown in fig. 5, it is specified that the preamble for SS block #0 is transmitted in RACH resource 1, the preamble for SS block #1 is transmitted in RACH resource 2, and the like according to the mapping rule. Using this mapping rule, the user equipment 200 selects RACH resource 1 when detecting PSS, SSs, or PBCH in SS block #0, and selects RACH resource 2 when detecting PSS, SSs, or PBCH in SS block # 1. The positions of RACH resource 1 and RACH resource 2 can be arbitrarily determined, and for example, RACH resource 1 and RACH resource 2 may be frequency-multiplexed in the same time.

In addition, all resources within 1 cycle of RACH resource configuration may not be used as RACH resources. For example, when it is assumed that mapping is performed only from SS blocks actually transmitted by the base station within the SS burst set, as shown in fig. 5, if only SS block #0 and SS block #1 are actually transmitted within the SS burst set, resources other than RACH resource 1 and RACH resource 2 may not be used for RACH. That is, the RACH resources remaining after one mapping is performed only from the SS blocks actually transmitted by the base station in the SS burst set may not be mapped from the SS blocks. Further, for example, when mapping is performed for the maximum number L of SS blocks in an SS burst set, if L is 4 and only SS block #1 among SS blocks #0 to #3 is actually transmitted, the RACH resources mapped by SS blocks #0, #2, and #3 may not be used for the RACH. The RACH resources after one mapping from the maximum number L of SS blocks in the SS burst set may not be mapped from the SS blocks. RACH resources not mapped from SS blocks #0 to #3 may not be used for RACH. The resource that is not used for the RACH in any of the above cases may be used for other purposes such as other channels (e.g., data channel and control channel).

Fig. 5 shows an example of selecting a RACH resource from the front among the resources within 1 cycle of the RACH resource configuration, but the RACH resource may be selected from the rear, and the RACH resource may be selected according to other rules.

In addition, in the last slot to which the SS block is mapped, there is a case where RACH resources are left. For example, in fig. 3, in the last slot to which the SS block #63 is mapped, only one RACH resource is used. In this case, the RACH resource may be used from the front of the time slot, may be used from the rear of the time slot, or may be used according to another rule. Further, when the RACH resource is frequency-multiplexed and the RACH resource in the frequency direction is left, the RACH resource may be used from a higher frequency, may be used from a lower frequency, or may be used according to another rule.

The user equipment 200 transmits a preamble to the base station 100 in the selected resource (S103). When receiving the preamble, the base station 100 can identify which SS block the user apparatus 200 can detect from the resource in which the preamble is received, based on the same mapping rule as the user apparatus 200. The base station 100 transmits RAR, which is response information, to the user apparatus 200 with respect to the received preamble. Then, a connection between the base station 100 and the user equipment 200 is established.

< example 2>

Next, specific example 2 of the preamble transmission procedure in the wireless communication system according to the present embodiment will be described in detail with reference to fig. 6. Fig. 6 is a schematic diagram of specific example 2 of selecting a resource for transmitting a preamble. In specific example 2, a preamble is also transmitted in accordance with the preamble transmission procedure of fig. 4. The following describes in detail the differences from example 1.

In step S101, the user equipment 200 determines resources that can be used for transmission of the preamble based on RACH configuration (RACHConfiguration) included in the broadcast information. For example, as shown in fig. 6, it is determined by RACH Configuration that 6 RACH resources can be used in the time direction in 1 cycle (cycle of RACH resource allocation) of a certain specified period.

The user equipment 200 selects a RACH resource associated with an SS block in which the detected PSS, SSs, or PBCH is arranged, from among resources that can be used for transmission of the preamble, using a mapping rule that specifies the correspondence relationship between the SS blocks in the SS burst set and the RACH resource. For example, as shown in fig. 6, it is specified that the preamble for SS block #0 is transmitted in RACH resource 1, the preamble for SS block #1 is transmitted in RACH resource 2, and the like according to the mapping rule. When the mapping period is 2 times or more the time that the mapping of all SS blocks in the SS burst set can be completed, the mapping from SS block #0 and SS block #1 is repeated in the remaining RACH resources. In the example of fig. 6, the mapping from SS block #0 and SS block #1 is repeated 3 times within 1 mapping period. The number of repetitions may be defined in the specification, or may be notified by the base station. Alternatively, the mapping may be repeated for 1 mapping period, with the maximum number of times the mapping from all SS blocks in the SS burst set is repeated. The RACH resources that are not mapped when based on the above may not be used in the RACH. Resources not used for RACH may also be used in other uses such as other channels (e.g., data channels, control channels).

In step S103, the user equipment 200 transmits a preamble to the base station 100 in the selected resource.

< specific example 3>

Next, specific example 3 of the preamble transmission procedure in the wireless communication system according to the present embodiment will be described in detail with reference to fig. 7. Fig. 7 is a schematic diagram of specific example 3 of selecting a resource for transmitting a preamble. In specific example 3, a preamble is also transmitted in accordance with the preamble transmission procedure of fig. 4. The following describes in detail the differences from example 1.

In step S101, the user equipment 200 determines resources that can be used for transmission of the preamble based on RACH configuration (RACHConfiguration) included in the broadcast information. For example, as shown in fig. 6, it is determined by RACH Configuration that 6 RACH resources can be used in the time direction and 4 RACH resources can be used in the frequency direction within 1 cycle (cycle of RACH resource allocation) of a certain specified period. That is, 4 RACH resources are frequency multiplexed at the same time.

The user equipment 200 selects a RACH resource associated with an SS block in which the detected PSS, SSs, or PBCH is arranged, from among resources that can be used for transmission of the preamble, using a mapping rule that specifies the correspondence relationship between the SS blocks in the SS burst set and the RACH resource. Here, when the number of RACH resources required for one SS block is 3, a preamble for SS block #0 is transmitted in RACH resource 1 in the first time. Since there is not a resource left enough to transmit the preamble for the SS block #1 in the first time, the remaining one RACH resource is not used for the SS block #1, and the RACH resource 2 of the next time is selected.

< functional Structure of base station >

Fig. 8 is a diagram showing an example of the functional configuration of the base station 100. The base station 100 includes a transmitter 110, a receiver 120, a setting information manager 130, and a random access controller 140. The functional configuration shown in fig. 8 is merely an example. The names of the function division and the function unit may be any names as long as the operation of the present embodiment can be performed.

The transmission unit 110 is configured to generate a signal of a lower layer from information of an upper layer and wirelessly transmit the signal. The transmission unit 110 transmits signals such as PSS, SSS, PBCH, and the like. The receiving unit 120 is configured to receive various signals wirelessly and acquire information on a higher layer from the received signals.

The Configuration information management unit 130 stores preset Configuration information, and determines and holds Configuration information (RACH Configuration, mapping rule, mapping cycle, any Configuration information used in the present embodiment, and the like) set for the user equipment 200. The setting information management unit 130 transfers the setting information set for the user apparatus 200 to the transmission unit 110, and causes the transmission unit 110 to transmit the setting information.

The random access control unit 140 manages a random access procedure with the user equipment 200. When receiving the preamble from the user apparatus 200, the transmitter 110 is caused to transmit the RAR, and when receiving the RRC connection request (RRC connection request) from the user apparatus 200, the transmitter 110 is caused to transmit the RRC connection setup (RRC connection setup).

< functional Structure of user device >

Fig. 9 is a diagram showing an example of the functional configuration of the user apparatus 200. The user equipment 200 includes a transmitter 210, a receiver 220, a setting information manager 230, a resource selector 240, and a random access controller 250. The functional configuration shown in fig. 9 is merely an example. The names of the function division and the function unit may be arbitrary as long as the operation of the present embodiment can be performed.

The transmission unit 210 is configured to generate a lower layer signal from the higher layer information and wirelessly transmit the signal. The transmission unit 210 transmits a preamble based on the setting information stored in the setting information management unit 230 described below. The receiving unit 220 is configured to receive various signals wirelessly and acquire information on a higher layer from the received signals. The reception unit 220 receives signals of PSS, SSS, PBCH, and the like from the base station 100. The receiving unit 220 receives Configuration information (RACH Configuration, mapping rule, mapping cycle, any Configuration information used in the present embodiment, and the like) from the base station 100 and the like.

The setting information management unit 230 stores setting information set in advance and also stores setting information set from the base station 100 and the like. The setting information that can be managed by the setting information management unit 230 includes not only setting information set from the base station 100 or the like but also setting information set in advance according to specifications.

The resource selection unit 240 determines resources that can be used for transmission of the preamble based on the setting information stored in the setting information management unit 230. The resource selection unit 240 selects an RACH resource to be used for transmitting a preamble from among the resources available for transmission of the preamble, based on the mapping rule stored in the setting information management unit 230.

The random access control unit 250 manages a random access procedure with the base station 100. When the user equipment 200 establishes a connection with the base station 100 or performs resynchronization due to a call origination or handover, the random access control unit 250 causes the transmission unit 210 to transmit a preamble randomly selected from the plurality of preambles. After the preamble is transmitted, if the RAR, which is response information of the preamble, is not received within a period called an RAR window, for example, the random access control unit 250 causes the transmission unit 210 to retransmit the preamble. When receiving the RAR from the base station 100, the random access control unit 250 causes the transmission unit 210 to transmit an RRC connection request (RRC connection request).

< example of hardware Structure >

The block diagrams used in the description of the above embodiments show blocks in units of functions. These functional blocks (structural parts) are realized by any combination of hardware and/or software. Note that means for realizing each functional block is not particularly limited. That is, each functional block may be implemented by one apparatus that is physically and/or logically combined, or may be implemented by a plurality of apparatuses that are directly and/or indirectly (for example, by wire and/or wirelessly) connected with two or more apparatuses that are physically and/or logically separated.

For example, the base station, the user equipment, and the like in one embodiment of the present invention may function as a computer that performs the processing of the preamble transmission method of the present invention. Fig. 10 is a diagram showing an example of a hardware configuration of a wireless communication apparatus which is the base station 100 or the user apparatus 200 according to the embodiment of the present invention. The base station 100 and the user apparatus 200 may be configured as a computer apparatus physically including a processor 1001, a memory 1002, a storage 1003, a communication apparatus 1004, an input apparatus 1005, an output apparatus 1006, a bus 1007, and the like.

In the following description, the term "device" may be replaced with "circuit", "device", "unit", and the like. The hardware configuration of the base station 100 and the user equipment 200 may include one or more of each illustrated device, or may be configured not to include a part of the device.

The functions in the base station 100 and the user equipment 200 are realized by the following methods: when predetermined software (program) is read from hardware such as the processor 1001 and the memory 1002, the processor 1001 performs an operation to control communication of the communication device 1004 and/or reading and/or writing of data in the memory 1002 and the storage 1003.

The processor 1001 operates, for example, an operating system to control the entire computer. The processor 1001 may be a Central Processing Unit (CPU) including an interface with a peripheral device, a control device, an arithmetic device, a register, and the like. For example, the transmitter 110, the receiver 120, the setting information manager 130, the random access controller 140 of the base station 100, the transmitter 210, the receiver 220, the setting information manager 230, the resource selector 240, the random access controller 250 of the user equipment 200, and the like can be realized by the processor 1001.

The processor 1001 reads out a program (program code), a software module, or data from the memory 1003 and/or the communication device 1004 to the memory 1002, and executes various processes. As the program, a program that causes a computer to execute at least a part of the operations described in the above embodiments is used. For example, the transmission unit 110, the reception unit 120, the setting information management unit 130, the random access control unit 140, the transmission unit 210, the reception unit 220, the setting information management unit 230, the resource selection unit 240, and the random access control unit 250 of the base station 100 may be realized by a control program stored in the memory 1002 and operated by the processor 1001, and may be realized similarly for other functional blocks. Although the above-described various processes are executed by 1 processor 1001, the above-described various processes may be executed by 2 or more processors 1001 at the same time or sequentially. The processor 1001 may be mounted by 1 or more chips. In addition, the program may be transmitted from the network via a telecommunication line.

The Memory 1002 is a computer-readable recording medium, and may be configured by at least one of a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), a RAM (Random access Memory), and the like. Memory 1002 may also be referred to as registers, cache, main memory (primary storage), etc. The memory 1002 can store a program (program code), a software module, and the like that can be executed to implement the preamble transmission method according to the embodiment of the present invention.

The storage 1003 is a computer-readable recording medium, and may be constituted by at least one of an optical disk such as a CD-rom (compact Disc rom), a hard disk drive, a flexible disk, a magneto-optical disk (for example, a compact Disc, a digital versatile Disc, a Blu-ray (registered trademark) Disc, a smart card, a flash memory (for example, a card, a stick, a Key drive), a Floppy (registered trademark) Disc, a magnetic stripe, and the like.

The communication device 1004 is hardware (a transmitting/receiving device) for performing communication between computers via a wired and/or wireless network, and may also be referred to as a network device, a network controller, a network card, a communication module, or the like. For example, the transmission unit 110, the reception unit 120, the transmission unit 210, the reception unit 220, and the like can be realized by the communication device 1004.

The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a key, a sensor, and the like) that receives an input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, or the like) that outputs to the outside. The input device 1005 and the output device 1006 may be integrally formed (for example, a touch panel).

Further, the processor 1001 and the memory 1002 are connected to each other via a bus 1007 for communicating information. The bus 1007 may be constituted by a single bus or may be constituted by different buses between devices.

The base station 100 and the user equipment 200 may be configured to include hardware such as a microprocessor, a Digital Signal Processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field Programmable gate Array), or the like, and a part or all of the functional blocks may be implemented by the hardware. For example, the processor 1001 may be installed through at least 1 of these hardware.

< summary of embodiments of the invention >

As described above, according to an embodiment of the present invention, there is provided a user apparatus including: a reception unit that detects a synchronization signal or a physical broadcast channel from a base station; a resource selection unit that selects a resource for transmitting a preamble from the detected synchronization signal or physical broadcast channel, based on a mapping rule, from among resources determined based on setting information for preamble transmission, according to a cycle determined based on a synchronization signal burst set cycle, which is a period during which the synchronization signal or physical broadcast channel can be transmitted, a resource cycle that can be used for transmission of the preamble, and a time during which mapping of the synchronization signal or broadcast channel in the synchronization signal burst set can be completed; and a transmission unit configured to transmit a preamble to the base station in the selected resource.

When the user equipment transmits the preamble, the period of the SS burst set or the period of the RACH resource allocation has a certain relationship with the mapping period from the SS block to the RACH resource, and therefore, the base station can recognize which SS block the user equipment 200 can detect from the resource in which the preamble is received.

After mapping from the synchronization signal or the physical broadcast channel in the synchronization signal burst set based on the mapping rule, among the resources determined based on the setting information for the preamble transmission, the resource that is not mapped may not be used for the preamble transmission, or, when the synchronization signal or the physical broadcast channel is not transmitted in the synchronization signal burst set, among the resources determined based on the setting information for the preamble transmission, the resource corresponding to the non-transmitted synchronization signal or the physical broadcast channel may not be used for the preamble transmission.

Although the Configuration of the RACH resources is determined in accordance with the RACH Configuration (RACH Configuration), since not all SS blocks in the SS burst set are used, it is possible to effectively use resources by using resources that are not used for the RACH in other applications.

When the period of mapping from the synchronization signal or the physical broadcast channel to the resource based on the mapping rule is 2 times or more the time in which mapping in the synchronization signal burst set can be completed, the resource selection unit may repeat mapping from the synchronization signal burst set to the resource a plurality of times within the period of mapping.

Thus, by transmitting the preamble a plurality of times, the probability that the base station can receive the preamble can be increased.

The resource selection unit selects a resource mapped from the 2 nd synchronization signal or the physical broadcast channel in a2 nd time different from the 1 st time, when the resource determined based on the setting information for the preamble transmission is frequency-multiplexed in the same time and sufficient resource required for mapping from the 2 nd synchronization signal or the physical broadcast channel in the synchronization signal burst set does not remain in the 1 st time of the resource mapped from the 1 st synchronization signal or the physical broadcast channel in the synchronization signal burst set.

When there is not enough resource left in the frequency direction at the same time, it is not necessary to switch the frequency range of the RACH resource to be transmitted to a SS block by using the resource at the next time.

< supplement >

The forms/embodiments described in this specification can also be applied to LTE (Long Term Evolution), LTE-a (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G, 5G, FRA (Future radio access), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra mobile Broadband), IEEE 802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE802.20, UWB (Ultra-wide band), Bluetooth (registered trademark), systems using other suitable systems, and/or next generation systems extended accordingly.

The terms "system" and "network" as used in this specification are used interchangeably.

In this specification, it is assumed that the specific operation performed by the base station is performed by an upper node (uplink) in some cases. It should be clear that in a network consisting of 1 or more network nodes (network nodes) with base stations, various actions to be performed for communication with terminals can be performed by the base stations and/or other network nodes (e.g., MME, S-GW, etc., but not limited thereto) other than the base stations. In the above, the case where there are 1 network node other than the base station is exemplified, but a combination of a plurality of other network nodes (e.g., MME and S-GW) may be employed.

Information and the like can be output from an upper layer (or a lower layer) to a lower layer (or an upper layer). Or may be input or output via a plurality of network nodes.

The input or output information and the like may be stored in a specific location (for example, a memory) or may be managed in a management table. Information to be input or output, etc. may be rewritten, updated, or appended. The output information may be deleted. The entered information may also be transmitted to other devices, etc.

The information is not limited to the form and embodiment described in the present specification, and may be notified by another method. For example, the notification of the Information may be performed by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), higher layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast Information (MIB (Master Information Block), SIB (system Information Block)), other signals, or a combination of these.

The determination may be made by a value (0 or 1) represented by 1 bit, may be made by a Boolean value (true or false), or may be made by comparison of numerical values (for example, comparison with a predetermined value).

Software shall be construed broadly to mean commands, command sets, codes, code segments, program codes, programs, subroutines, software modules, applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names.

Further, software, commands, and the like may be transmitted and received via a transmission medium. For example, where the software is transmitted from a web page, server, or other remote source using a wired technology such as coaxial cable, fiber optic cable, twisted pair, and Digital Subscriber Line (DSL), and/or a wireless technology such as infrared, wireless, and microwave, the wired and/or wireless technologies are included in the definition of transmission medium.

Information, signals, etc. described herein may be represented using any of a variety of different technologies and techniques. For example, data, commands, instructions (commands), information, signals, bits, symbols (symbols), chips (chips), etc., that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or photons, or any combination thereof.

Further, terms described in the present specification and/or terms necessary for understanding the present specification may be replaced with terms having the same or similar meanings. For example, the channel and/or symbol may also be a signal (signal). Further, the signal may also be a message. Further, Component Carriers (CCs) may also be referred to as carrier frequencies, cells, and the like.

The information, parameters, and the like described in the present specification may be expressed in absolute values, relative values to predetermined values, or other corresponding information. For example, the radio resource may also be indicated by an index.

The names used in the above parameters should not be construed in any way as limiting. Further, the numerical expressions and the like using these parameters may be different from the expressions explicitly disclosed in the present specification. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements (e.g., TPC, etc.) can be identified by any suitable names, and thus, the various names assigned to these various channels and information elements should not be construed in any way as limiting.

The terms "determining" and "determining" used in the present specification may include various operations. The "determination" and "decision" may include, for example, an event in which an event that has been calculated (computing), processed (processing), derived (deriving), investigated (analyzing), searched (searching in a table, a database, or another data structure), or confirmed (ascertaining) is regarded as "determination" or "decision". The "determination" and "decision" may include a matter in which reception (e.g., reception information), transmission (e.g., transmission information), input (input), output (output), and access (e.g., access to data in a memory) are performed as "determination" and "decision". The "judgment" and "decision" may include matters regarding the solution (resolving), selection (selecting), selection (breathing), establishment (evaluating), comparison (comparing), and the like as the "judgment" and "decision". That is, the terms "determining" and "deciding" may include any action.

As used herein, the term "according to" is not intended to mean "only according to" unless explicitly stated otherwise. In other words, such recitation of "according to" means both "according only" and "at least according to".

Any reference to elements using the designations "1 st", "2 nd", etc. used in this specification is not intended to limit the number or order of such elements. These designations can be used in the present specification as a simple method for distinguishing 2 or more elements. Thus, references to elements 1 and 2 do not mean that only 2 elements can be employed herein, or that the 1 st element must precede the 2 nd element in some fashion.

The terms "including", "including" and variations thereof, as used herein in the specification or the claims, are intended to be inclusive in the same manner as the term "comprising". Also, the term "or" as used in the specification or claims means not exclusive or.

The order of the processing procedures, sequences, flows, and the like of the respective forms and embodiments described in this specification may be changed without departing from the scope of the invention. For example, elements of the various steps are presented in an exemplary order for the methods described in this specification, but are not limited to the specific order presented.

The respective aspects and embodiments described in the present specification may be used alone, may be used in combination, or may be switched depending on execution. Note that the notification of the predetermined information (for example, the notification of "X") is not limited to an explicit notification, and may be performed implicitly (for example, without performing the notification of the predetermined information).

While the present invention has been described in detail, it should be apparent to those skilled in the art that the present invention is not limited to the embodiments described in the present specification. The present invention can be implemented as modifications and variations without departing from the spirit and scope of the present invention defined by the claims. Therefore, the description of the present invention is for illustrative purposes and is not intended to limit the present invention in any way.

The international application claims the priority of the japanese laid-open application No. 2018-010498 applied on 25/1/2018, and the international application cites the entire content of the japanese laid-open application No. 2018-010498.

Description of the reference symbols

100: a base station; 110: a transmission unit; 120: a receiving section; 130: a setting information management unit; 140: a random access control unit; 200: a user device; 210: a transmission unit; 220: a receiving section; 230: a setting information management unit; 240: a resource selection unit; 250: and a random access control unit.

Claims

1. A user device, wherein the user device has:

a control unit that selects a resource for transmitting a preamble from the detected synchronization signal or physical broadcast channel, based on a mapping rule, from among resources determined based on setting information for preamble transmission, according to a cycle determined based on a synchronization signal burst set cycle, which is a period during which the synchronization signal or physical broadcast channel can be transmitted, a resource cycle that can be used for preamble transmission, and a time during which mapping of the synchronization signal or broadcast channel in the synchronization signal burst set can be completed; and

2. The user device of claim 1,

after mapping from the synchronization signal or the physical broadcast channel in the synchronization signal burst set based on the mapping rule, among the resources determined based on the setting information for the preamble transmission, the resource that is not mapped is not used for the preamble transmission, or, when the synchronization signal or the physical broadcast channel is not transmitted in the synchronization signal burst set, among the resources determined based on the setting information for the preamble transmission, the resource corresponding to the non-transmitted synchronization signal or the physical broadcast channel is not used for the preamble transmission.

3. The user device of claim 1 or 2,

when the period of mapping from the synchronization signal or the physical broadcast channel to the resource based on the mapping rule is 2 times or more of the time in which mapping in the synchronization signal burst set can be completed, the control unit repeats mapping from the synchronization signal or the physical broadcast channel to the resource a plurality of times within the period of mapping.

4. The user device according to any one of claims 1 to 3,

the control unit selects a resource mapped from the 2 nd synchronization signal or the physical broadcast channel in a2 nd time different from the 1 st time, when the resource determined based on the setting information for the preamble transmission is frequency-multiplexed in the same time and a resource necessary for mapping from the 2 nd synchronization signal or the physical broadcast channel in the synchronization signal burst set is not left in the 1 st time of the resource mapped from the 1 st synchronization signal or the physical broadcast channel in the synchronization signal burst set.

5. A preamble transmission method in a user equipment, wherein the preamble transmission method has the steps of:

detecting a synchronization signal or a physical broadcast channel from a base station;

selecting a resource for transmitting a preamble from the detected synchronization signal or physical broadcast channel based on a mapping rule, from among resources determined based on setting information for preamble transmission, according to a cycle determined based on a cycle of a synchronization signal burst set, which is a period during which the synchronization signal or physical broadcast channel can be transmitted, a cycle of a resource that can be used for transmission of the preamble, and a time during which mapping of the synchronization signal or broadcast channel in the synchronization signal burst set can be completed; and

transmitting a preamble to the base station in the selected resource.